package org.drools.examples.shopping;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.FactHandle;

public class ShoppingExample {

	public static final void main(String[] args) {
		final KnowledgeBuilder kbuilder = KnowledgeBuilderFactory
				.newKnowledgeBuilder();
		kbuilder.add(ResourceFactory.newClassPathResource("Shopping.drl",
				ShoppingExample.class), ResourceType.DRL);

		final KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
		kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());

		final StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();

		Customer mark = new Customer("mark", 0);
		ksession.insert(mark);

		Product shoes = new Product("shoes", 60);
		ksession.insert(shoes);

		Product hat = new Product("hat", 60);
		ksession.insert(hat);

		ksession.insert(new Purchase(mark, shoes));

		FactHandle hatPurchaseHandle = ksession.insert(new Purchase(mark, hat));

		ksession.fireAllRules();

		ksession.retract(hatPurchaseHandle);
		System.out.println("Customer mark has returned the hat");
		ksession.fireAllRules();
	}

	public static class Customer {
		private String name;

		private int discount;

		public Customer(String name, int discount) {
			this.name = name;
			this.discount = discount;
		}

		public String getName() {
			return name;
		}

		public int getDiscount() {
			return discount;
		}

		public void setDiscount(int discount) {
			this.discount = discount;
		}

	}

	public static class Discount {
		private Customer customer;
		private int amount;

		public Discount(Customer customer, int amount) {
			this.customer = customer;
			this.amount = amount;
		}

		public Customer getCustomer() {
			return customer;
		}

		public int getAmount() {
			return amount;
		}

	}

	public static class Product {
		private String name;
		private float price;

		public Product(String name, float price) {
			this.name = name;
			this.price = price;
		}

		public String getName() {
			return name;
		}

		public float getPrice() {
			return price;
		}

	}

	public static class Purchase {
		private Customer customer;
		private Product product;

		public Purchase(Customer customer, Product product) {
			this.customer = customer;
			this.product = product;
		}

		public Customer getCustomer() {
			return customer;
		}

		public Product getProduct() {
			return product;
		}
	}
}
